Adjustment method of NT855 valve of Cummins diesel generator

The valve adjustment method is that the valve clearance can only be adjusted when the valve is completely closed, and the rocker arm must fall on the base circle of the cam. That is, the intake valve that is intake, about to intake and just after exhaust cannot be adjusted.

Loosen the adjusting nuts of the injector rocker arms of all cylinders, and you can clearly see which cylinders have been adjusted and which cylinders have not been adjusted in the future.

Excessive valve clearance will make the valve open late and close early. Shortening the opening time will reduce the maximum valve stroke and increase the intake and exhaust resistance.

The intake valve closes too early, and the airflow inertia cannot be fully utilized; The exhaust valve is closed too early and the exhaust time is short, so the airflow inertia can not be fully utilized.

Extended data

1. When replacing the cylinder gasket and piston ring of the diesel generator set, or fastening the cylinder head according to the specified torque due to air leakage of the cylinder gasket, the valve clearance must be adjusted.

2. Excessive valve clearance will cause the valve to open late and close early (under normal circumstances, the intake valve will open early and the exhaust valve will close late), the air intake is insufficient, the exhaust is not clean, and the exhaust noise of the diesel engine is too high. However, if the valve clearance is too small, it will cause the valve to close loosely, ablate or leak.

3. When installing the valve, the intake valve cannot be mixed with the exhaust valve, because the exhaust valve is subjected to high temperature, and the valve is installed backwards, which will cause the door to burn through.

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